package com.example.demo.filter;

import com.alibaba.fastjson.JSONObject;


import com.example.demo.common.Result;
import com.example.demo.utils.JwtUtils;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;


import java.io.IOException;
@Slf4j
@WebFilter(urlPatterns = "/*")
public class LoginJwtFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException, ServletException, ServletException {
        HttpServletRequest req = (HttpServletRequest) servletRequest;//转为子接口
        HttpServletResponse resp = (HttpServletResponse) servletResponse;

        //1.获取请求url
        String url = req.getRequestURI();
        log.info("请求的url:{}",url);

        //2.判断请求中是否包含url,如果包含,说明是登录操作,放行
        if (url.contains("login")){
            log.info("登录操作,放行...");
            filterChain.doFilter(servletRequest, servletResponse);
            return;
        }

        //3.不是登录操作,获取请求头中的令牌(token)
        String jwt = req.getHeader("token");

        //4.判断令牌是否存在,如果不存在,返回错误结果(未登录).
        if(!StringUtils.hasLength(jwt)){
            log.info("请求头token,返回未登录的信息");
            Result error = Result.error("NOT_LOGIN");
            //手动转换 对象--json ---->阿里巴巴fastJSON
            String notLogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notLogin);//响应给浏览器
            return;
        }

        //5.解析token,如果解析失败,返回错误结果(未登录)
        try {
            JwtUtils.parseJWT(jwt);
        } catch (Exception e) {
            e.printStackTrace();
            log.info("解析令牌失败,返回未登录错误信息");
            Result error = Result.error("NOT_LOGIN");
            //手动转换 对象--json ---->阿里巴巴fastJSON
            String notLogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notLogin);//响应给浏览器
            return;
        }

        //6.放行
        log.info("令牌合法,放行");
        filterChain.doFilter(servletRequest, servletResponse);


    }
}
